1. Field of the Invention
This invention relates to cultivated varieties of true breeding, stable, tetraploid perennial ryegrass, for use as a short lived, improved turfgrass on golf courses, athletic fields and other areas using seeded turfgrasses.
2. Background of the Art
Tetraploid perennial ryegrass is commonly used as a forage grass. It is not used, nor recommended, for turfgrass use. Typical tetraploid ryegrass produces an open sward and has a very rapid vertical extension rate. Commercial varieties are light green in color. There are no commercially available varieties of tetraploid perennial ryegrass available for permanent or overseeding turf use.
A stable variety of tetraploid perennial ryegrass would be a desirable grass for use in overseeding of dormant warm season grasses since its lack of heat tolerance allows for a smooth transition for the warm-season grass. Tetraploid perennial ryegrass will provide a green cover during the winter months but will die out when the temperatures increase which allow the warm-season grass to grow.
For many southern golf courses planted with Bermuda grass, a standard practice is to overseed every fall with diploid perennial ryegrass. Diploid perennial ryegrass provides an outstanding turf cover during the cool winter months. However, diploid perennial ryegrass is very persistent and does not easily die out and give way for the re-emerging Bermuda grass in the spring when warm weather returns.
Turfgrass managers could utilize a cultivar that has a dark green color, rapid establishment, and the ability to transition rapidly. The two most widely used species for overseeding are annual and diploid perennial ryegrass. Annual ryegrass, such as the variety ‘Gulf,’ have an undesirable color and a very rapid vertical extension rate which results in frequent mowing. Diploid perennial ryegrass has been developed for heat tolerance and permanent turf use and therefore does not transition well.